fix(ui): improve speed of dashboard by caching data (#224)

Contents/Code/default_prefs.py

@@ -12,6 +12,7 @@
     bool_update_collection_metadata_plex_movie='False',
     bool_update_collection_metadata_legacy='True',
     int_update_themes_interval='60',
+    int_update_database_cache_interval='60',
     int_plexapi_plexapi_timeout='180',
     int_plexapi_upload_retries_max='3',
     int_plexapi_upload_threads='3',

Contents/Code/scheduled_tasks.py

@@ -21,6 +21,7 @@
 # local imports
 from constants import plugin_identifier
 from plex_api_helper import scheduled_update
+from webapp import cache_data
 
 # setup logging for schedule
 Log.Info('Adding schedule log handlers to plex plugin logger')
@@ -112,5 +113,9 @@ def setup_scheduling():
             job_func=run_threaded,
             target=scheduled_update
         )
+        schedule.every(max(15, int(Prefs['int_update_database_cache_interval']))).minutes.do(
+            job_func=run_threaded,
+            target=cache_data
+        )
 
     run_threaded(target=schedule_loop, daemon=True)  # start the schedule loop in a thread

Contents/Code/webapp.py

@@ -7,7 +7,7 @@
 import json
 import logging
 import os
-from threading import Thread
+from threading import Lock, Thread
 
 # plex debugging
 try:
@@ -16,6 +16,7 @@
     pass
 else:  # the code is running outside of Plex
     from plexhints.constant_kit import CACHE_1DAY  # constant kit
+    from plexhints.core_kit import Core  # core kit
     from plexhints.log_kit import Log  # log kit
     from plexhints.parse_kit import JSON  # parse kit
     from plexhints.prefs_kit import Prefs  # prefs kit
@@ -28,7 +29,7 @@
 from werkzeug.utils import secure_filename
 
 # local imports
-from constants import contributes_to, issue_urls, plugin_directory, plugin_identifier
+from constants import contributes_to, issue_urls, plugin_directory, plugin_identifier, themerr_data_directory
 import general_helper
 from plex_api_helper import get_database_info, setup_plexapi
 import themerr_db_helper
@@ -100,6 +101,10 @@
     'svg': 'image/svg+xml',
 }
 
+# where the database cache is stored
+database_cache_file = os.path.join(themerr_data_directory, 'database_cache.json')
+database_cache_lock = Lock()
+
 
 @babel.localeselector
 def get_locale():
@@ -182,30 +187,14 @@ def stop_server():
     return False
 
 
-@app.route('/', methods=["GET"])
-@app.route('/home', methods=["GET"])
-def home():
-    # type: () -> render_template
+def cache_data():
+    # type: () -> None
     """
-    Serve the webapp home page.
-
-    This page serves the Themerr completion report for supported Plex libraries.
-
-    Returns
-    -------
-    render_template
-        The rendered page.
+    Cache data for use in the Web UI dashboard.
 
-    Notes
-    -----
-    The following routes trigger this function.
-
-        - `/`
-        - `/home`
-
-    Examples
-    --------
-    >>> home()
+    Because there are many http requests that must be made to gather the data for the dashboard, it can be
+    time-consuming to populate; therefore, this is performed within this caching function, which runs on a schedule.
+    This function will create a json file that can be loaded by other functions.
     """
     # get all Plex items from supported metadata agents
     plex_server = setup_plexapi()
@@ -368,7 +357,45 @@ def home():
                 year=year,
             ))
 
-    return render_template('home.html', title='Home', items=items)
+    with database_cache_lock:
+        Core.storage.save(filename=database_cache_file, data=json.dumps(items), binary=False)
+
+
+@app.route('/', methods=["GET"])
+@app.route('/home', methods=["GET"])
+def home():
+    # type: () -> render_template
+    """
+    Serve the webapp home page.
+
+    This page serves the Themerr completion report for supported Plex libraries.
+
+    Returns
+    -------
+    render_template
+        The rendered page.
+
+    Notes
+    -----
+    The following routes trigger this function.
+
+        - `/`
+        - `/home`
+
+    Examples
+    --------
+    >>> home()
+    """
+    items = []
+    try:
+        items = json.loads(Core.storage.load(filename=database_cache_file, binary=False))
+    except IOError:
+        pass
+
+    if items:
+        return render_template('home.html', title='Home', items=items)
+    else:
+        return render_template('home_db_not_cached.html', title='Home')
 
 
 @app.route("/<path:img>", methods=["GET"])

Contents/DefaultPrefs.json

@@ -76,6 +76,13 @@
 		"default": "60",
 		"secure": "false"
 	},
+	{
+		"id": "int_update_database_cache_interval",
+		"type": "text",
+		"label": "Interval for database cache update task, in minutes (min: 15)",
+		"default": "60",
+		"secure": "false"
+	},
 	{
 		"id": "int_plexapi_plexapi_timeout",
 		"type": "text",

Contents/Resources/web/templates/home_db_not_cached.html

@@ -0,0 +1,16 @@
+{% extends 'base.html' %}
+{% block modals %}
+{% endblock modals %}
+
+{% block content %}
+<div class="container px-auto my-5">
+    <div class="col-lg-12 mx-auto" id="themerr-container" style="min-width: 335px">
+
+        <h2 class="text-center text-white">{{ _('Database is being cached, please try again soon.') }}</h2>
+
+    </div>
+</div>
+{% endblock content %}
+
+{% block scripts %}
+{% endblock scripts %}

docs/source/about/usage.rst

@@ -173,6 +173,18 @@ Default
 Minimum
    ``15``
 
+Interval for database cache update task
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Description
+   The interval (in minutes) to run the database cache update task. This data is used to display the Web UI dashboard.
+
+Default
+   ``60``
+
+Minimum
+   ``15``
+
 PlexAPI Timeout
 ^^^^^^^^^^^^^^^
 
@@ -234,7 +246,7 @@ YouTube Cookies
 ^^^^^^^^^^^^^^^^
 
 Description
-   The cookies to use for the requests to YouTube. Should be in Chromium JSON export format. 
+   The cookies to use for the requests to YouTube. Should be in Chromium JSON export format.
    `Example exporter <https://chrome.google.com/webstore/detail/get-cookiestxt/bgaddhkoddajcdgocldbbfleckgcbcid>`__.
 
 Default

tests/unit/test_webapp.py

@@ -0,0 +1,18 @@
+# -*- coding: utf-8 -*-
+
+# standard imports
+import json
+import os
+
+# local imports
+from Code import webapp
+
+
+def test_cache_data():
+    webapp.cache_data()
+    assert os.path.isfile(webapp.database_cache_file), "Database cache file not found"
+
+    with open(webapp.database_cache_file, 'r') as f:
+        data = json.load(f)
+
+    assert data, "Database cache file is empty"